Tracing a Wet Past and Diverse Provenances in Gale Crater, Mars, With Lithium Content Using ChemCam on the Curiosity Rover

Abstract The incompatible behavior of Lithium during magmatic differentiation and high mobility during aqueous alteration make it a valuable tracer of crustal processes on Mars. Its preferential incorporation into secondary phyllosilicates further links Li to clay‐forming environments, which are critical for evaluating past aqueous activity and habitability. The ChemCam instrument aboard the Mars Science Laboratory Curiosity rover enables remote Li detection through laser‐induced breakdown spectroscopy (LIBS) and has provided the first in situ measurements of Li in Martian rocks. Here, we present the first stratigraphically contextualized analysis of Li abundance and variability in Gale crater based on almost 14,000 ChemCam observations across seven major bedrock classes. Lithium abundances are elevated relative to Martian meteorites, particularly shergottites, and broadly track phyllosilicate distribution, increasing in clay‐rich units and decreasing where phyllosilicates are absent. However, this relationship breaks down in the Clay‐sulfate Transition region, where Li remains elevated despite low phyllosilicate content. The persistence of high Li in this region, as well as in basaltic rocks, points to the presence of a Li‐enriched igneous provenance near Gale crater and emphasizes that the Martian crust is more compositionally diverse than that inferred from Martian meteorites alone.